Biofuels Can At Most Supply Half of Global Fuel Demand Before Cutting Into Food Production

It's a few years behind the now-passed biofuels-as-panacea hype, but research published in the Environmental Science and Technology finds that while a fairly significant amount of the current global liquid fuel demand can be satisfied by biofuels, without cutting into agricultural land, it's a far, far way from being a full substitute for fossil fuels.Within the boundaries of determining how much land around the globe could be used to produce grass crops for biofuels with "minimal impact on agriculture or the environment," civil and environmental engineering professor Ximing Cai's team from the University of Illinois at Urbana-Champaign concludes that about 1,107 million hectares (4.27 million square miles) could be put into biofuel production. That's enough for 26-56% of current liquid fuel demand--there are obviously lots a variables at play.

That billion hectare figure includes so-called marginal grassland, which could be used to grow low-impact high-diversity grasses that, though they have lower yields than other biofuel grasses such as miscanthus or switchgrass, can be still harvested to produce energy while at the same time maintaining grassland.

If only idle land and land with marginally productive land is included, the amount of land available for biofuels is about half the high estimate above.

Perhaps There Is A Renewable Future For Aviation After AllThe takeaway: Biofuels have an important role to play in future energy usage, but it is likely far less than biofuel companies would like. The gap between what can be produced without eating into land currently used for food production and total demand is vast.

That said, consider that a rough estimate of how much land would be required to grow biofuel crops for aviation and the current demand for aviation fuel, which comes in at about 424,700 square miles--well under the available land globally as determined by this report. If we electrified ground transport, increasing public transportation and building many more walkable communities as well, perhaps it is possible to keep aviation aloft with renewable fuels.